Brake apparatus with a combined brake cylinder and reservoir

ABSTRACT

This invention relates to a novel railway vehicle brake apparatus that comprises a brake cylinder device having two tandem-connected pistons of unequal size, the larger of which is provided with a check valve and cooperates with a hollow cylindrical body in which it is slidably disposed to form on its respective opposite sides two fluid pressure storage reservoirs wherein is stored fluid under pressure for effecting a brake application. This brake apparatus further comprises a novel brake control valve device that is so responsive to a reduction of pressure in a train brake pipe as to first cause simultaneous shifting of both pistons in a brake-applying direction and a transfer of fluid under pressure from one side of the larger piston to the other until a chosen braking force is transmitted through brake rigging to press brake shoes against the wheels of a vehicle. Thereafter, the control valve device is operative to release fluid under pressure from the one side of the larger piston to atmosphere to increase the braking force pressing the shoes against the wheels.

BACKGROUND OF THE INVENTION

The brake apparatus installed on railway freight cars being built at thepresent time includes a brake control valve device that is substantiallythe same as the brake control valve device shown and described in U.S.Pat. No. 3,175,869, issued Mar. 30, 1965, to Walter B. Kirk and assignedto the assignee of the present application, and a brake cylinder devicethat is substantially the same as the brake cylinder device shown anddescribed in U.S. Pat. No. 3,183,795, issued May 18, 1965, to Walter B.Kirk and also assigned to the assignee of the present application.

Moreover, as is shown in the above-mentioned U.S. Pat. No. 3,175,869,this railway freight car brake apparatus further includes an auxiliaryreservoir and an emergency reservoir which are charged with fluid underpressure from the usual train brake pipe when a brake release iseffected, and from which reservoirs fluid under pressure is supplied tothe brake cylinder to cause brake shoes to be pressed against the wheelsof the freight car when a brake application is effected.

Since these two fluid pressure storage reservoirs are separate itemsthat are necessary in addition to the brake control valve device and thebrake cylinder device required for each freight car, it is readilyapparent that they increase the total cost of the brake apparatusrequired on each car.

Accordingly, it is the general purpose of this invention to provide arailway freight car brake apparatus that comprises a novel brakecylinder device that embodies a pair of tandem-connected pistons ofunequal diameter, the larger piston cooperating with the brake cylinderbody to form on the respective opposite sides of this piston tworeservoirs that are charged with fluid under pressure from a train brakepipe. A novel brake control valve device responsive to variations ofpressure in the train brake pipe effects the establishment of fluidunder pressure forces on the one or the other sides of the two pistonsto cause a brake application and a subsequent brake release.

SUMMARY OF THE INVENTION

According to the present invention, a railway freight car fluid pressurebrake apparatus comprises a novel brake cylinder device that embodies apair of tandem-connected pistons of unequal size, each beingrespectively slidably mounted in a bore in one of a pair of separatehollow cylindrical members. The smaller cylindrical member is disposedwithin the larger cylindrical member on one side of the larger pistonwhich divides the larger hollow cylindrical member into two fluidpressure storage reservoirs. The larger piston is provided with a checkvalve to enable flow of fluid under pressure from the reservoir at oneside of this piston to the reservoir at the other side. The adjacentsides of the two pistons are connected by a first piston rod and theother side of the larger piston is connected by a larger piston rod andsuitable brake rigging to one or more braking elements for effecting abrake application on the tread surface of one or more wheels of thefreight car.

A novel brake control valve device is effective, in response to fullycharging a train brake pipe, to charge the two storage reservoirs on therespective opposite sides of the larger piston, and also a chamber onthe adjacent side of the smaller piston, to the fully charged pressurein the train brake pipe. This brake control valve device is thereafterresponsive to a reduction of the pressure in the train brake pipe tosimultaneously cause the release of fluid under pressure from thechamber on the adjacent side of the smaller piston to atmosphere andalso on equalization of pressure of the fluid under pressure in the twostorage reservoirs on the respective opposite sides of the larger pistoninto a chamber on the other side of the smaller piston to thereby effectsimultaneous shifting of the two pistons to a brake application positionin which a chosen limited degree of braking force is transmitted throughthe brake rigging to the braking elements.

Thereafter, this brake control valve device is operative in response tothe reduction of the pressure in the train brake pipe to effect acorresponding reduction of the equalized pressure in the reservoir atthe one side of the larger piston thereby rendering the fluid underpressure in the reservoir at the other side of this larger pistoneffective to increase the braking force transmitted to the brakingelements in accordance with the degree of the reduction of the pressurein the train brake pipe.

In the accompanying drawings:

FIG. 1 is a cross-sectional view of a pipe bracket that has a novelbrake cylinder device secured to its right-hand side and a novel brakecontrol valve device secured to its left-hand side.

FIG. 2 is a vertical cross-sectional view of the novel brake cylinderdevice shown in outline in FIG. 1.

FIG. 3A and FIG. 3B, taken together, constitute a diagrammatic view, insection, of the novel brake control valve device shown in outline inFIG. 1.

DESCRIPTION

As shown in FIG. 1 of the drawings, a novel railway freight car fluidpressure brake apparatus constituting the present invention comprises apipe bracket 1 that has a horizontal leg 2 and a vertical leg 3. Thevertical leg 3 has gasket faces 4 and 5 disposed opposite each other.

The brake apparatus shown in FIG. 1 further comprises a novel brakecontrol valve device 6 secured to the gasket face 4 on the left-handside of the vertical leg 3 of the pipe bracket 1, and a novel brakecylinder device 7 secured to the gasket face 5 on the right-hand side ofthis leg 3, a ported gasket 8 being disposed between the gasket face 4on the leg 3 and a gasket face 9 on the right-hand side of the brakecontrol valve device 6.

As shown in FIG. 2, the novel brake cylinder device 7 comprises a hollowcylindrical member 10 that may be in the form of a casting that hasformed integral with its right-hand end an inturned flange 11. Adjacentits left-hand end an out-turned flange 12 is formed integral therewith.This out-turned flange 12 is provided with a plurality ofarcuately-arranged smooth bores 13, only one of which appears in FIG. 1.

Formed in cylindrical member 10, as by machining, is a counterbore 14that extends inward from the left-hand end of this cylindrical member tothe inturned flange 11. Slidably mounted in the counterbore 14 is afirst fluid-pressure-actuated brake-applying piston 15.

In order to provide a seal between the wall of the counterbore 14 andthe piston 15, there is provided an annular packing cup 16 that isdisposed on the left-hand side of this piston 15. This packing cup 16has an outer portion 17 that is U-shaped in contour, with the inner legthereof merging with or abutting the left-hand side of the piston 15 andthe outer leg slidably engaging the wall surface of the counterbore 14for preventing leakage of fluid under pressure from the left-hand sideof the piston 15 to the right-hand side.

The left-hand end of the counterbore 14 is closed by a pressure head 18that is secured to the left-hand end of the cylindrical member 10 by aplurality of bolts 19 that extend through the bores 13 in the out-turnedflange 12 and a like number of arcuately-arranged smooth bores 20 in thepressure head 18 and a like number of nuts 21 that have screw-threadedengagement with these bolts 19, only one of which appears in FIG. 2.

The pressure head 18 is secured to the gasket face 5 (FIG. 1) on theright-hand side of the leg 3 of the pipe bracket 1 by a plurality ofstuds 22, two of which appear in FIG. 2, and nuts 23, the left-handscrew-threaded end of these studs 22 having screw-threaded engagementwith internal screw threads provided in a like number of bottomed bores24 in the leg 3 of pipe bracket 1.

As shown in FIG. 2, the right-hand end of the counterbore 14 is closedby a second pressure head 25 that at its left-hand end has formedintegral therewith an out-turned flange 26 which abuts the inturnedflange 11 that is integral with the right-hand end of the cylindricalmember 10.

Adjacent its right-hand end, the cylindrical member 10 is provided withan out-turned flange 27, the outer diameter of which is the same as thatof the out-turned flange 26. These out-turned flanges 26 and 27 areprovided with a plurality of arcuately-spaced coaxial smooth boresthrough which extend a like number of bolts 28, only two of which appearin FIG. 2. A nut 29 screw-threaded onto the end of each bolt 28 clampsthe out-turned flange 26 against the inturned flange 11.

The flange 11 is provided with two concentric grooves in which aredisposed a pair of annular gaskets 30 and 31 that form a seal with theout-turned flange 26 to prevent leakage of fluid under pressure from apressure chamber or storage reservoir 32 formed by the cylindricalmember 10, piston 15 and pressure head 25.

Formed integral with the right-hand side of the piston 15 is an annularboss 33 into which is press-fitted one end of a hollow rod 34 thatextends through a bore 35 in an annular boss 36 formed on the right-handend of the pressure head 25. The wall of the bore 35 is provided with apair of spaced-apart annular grooves in each of which is disposed anO-ring seal 37 that forms a seal with the outer periphery of the hollowrod 34 to prevent leakage of fluid under pressure from the pressurechamber 32 to atmosphere.

A piston rod (not shown) may be disposed within the hollow rod 34 andconnected through a suitable brake rigging (not shown) to brake shoes(not shown) that may be forced against the tread surface of the wheelsof a railway vehicle to effect a brake application thereon.

A rubber boot 38 surrounds that portion of the hollow rod 34 thatextends outside of the pressure head 25 to protect the outside smoothsurface of this rod 34 from damage by such as a piece of flying ballastfrom a railroad roadbed.

As shown in FIG. 2, the left-hand side of the piston 15 is provided withan annular bead 39. On the inside of this bead 39 the piston 15 isprovided with a plurality of arcuately-spaced bores 40, two of whichappear in FIG. 2. Flow of fluid under pressure from the pressure chamber32 on the right-hand side of the piston 15 to a pressure chamber orstorage reservoir 41 on the left-hand side of this piston via the bores40 is normally closed by a one-way valve device 42 that will now bedescribed in detail.

An annular metallic member 43 is embedded in an annular member 44 thatis made from some suitable resilient material such as, for example,rubber. The inner periphery of this resilient annular member 44 isclamped between a central boss 45 formed on the left-hand side of thepiston 15 and a cup-shaped spring seat 46 that is secured to the piston15 by a plurality of arcuately-arranged cap screws 47, two of whichappear in FIG. 2. A spring 48 interposed between the spring seat 46 andthe annular metallic member 43, as shown in FIG. 2, normally biases theresilient annular member 44 against the annular bead 39 to closecommunication between chamber 32 and chamber 41, which chambersconstitute two fluid pressure storage reservoirs that are charged withfluid under pressure in a manner hereinafter described.

The novel brake cylinder device 7 further comprises a positioningcylinder device 49 that is disposed within the chamber 41, as shown inFIG. 2. This positioning cylinder device 49 comprises a cup-shapedcylinder body 50, the left-hand end of which is provided with anout-turned flange 51 that has a plurality of arcuately-arranged smoothbores 52 which are coaxial with a like number of arcuately-arrangedsmooth bores 53 in the pressure head 18, one of these bores 52 and 53appearing in FIG. 2 of the drawings. A plurality of bolts 54, one ofwhich appears in FIG. 2, extend through the bores 52 and 53 and havescrew-threaded engagement with a like number of nuts 55 that aredisposed within recesses 56 (FIG. 1) provided therefor in the gasketface 5 on the right-hand side of the leg 3 of the pipe bracket 1. Thus,the bolts 54 and nuts 55 secure the positioning cylinder device 49 tothe pressure head 18 within the pressure chamber 41.

As shown in FIG. 2, the cylinder body 50 is provided with a bore 57 anda coaxial counterbore 58. Slidably mounted within the counterbore 58 isan annular piston 59 that has secured to its respective opposite sides apair of annular packing cups 60 and 61, each having an outer portionthat is U-shaped in contour so as to form a seal with the wall surfaceof the counterbore 58. These packing cups 60 and 61 and the piston 59thus form a pair of chambers 62 and 63 on the respective opposite sidesof the piston 59.

The piston 59 is operatively connected to the piston 15 by a piston rod64 that has formed on its right-hand end a collar 65 that abuts ascrew-threaded boss 66 formed on the left-hand side, as viewed in FIG.2, of the spring seat 46. A cup-shaped nut 67 surrounds the collar 65and has screw-threaded engagement with the screw threads on the boss 66to connect the piston rod 64 to the piston 15.

Adjacent its left-hand end, the piston rod 64 is provided with a portion68 of reduced diameter that has a shoulder 69 at its right-hand end andscrew threads extending inward a chosen distance from its left-hand end.A first annular plate 70 abuts the shoulder 69 and also the right-handside of the packing cup 60 while a second annular plate 71 is disposedbetween the left-hand side of the packing cup 61 and a nut 72 that hasscrew-threaded engagement with the screw threads on the portion 68.Thus, the nut 72 and plates 70 and 72 serve to rigidly secure the piston59 to the piston rod 64.

An O-ring seal 73 is disposed in a peripheral annular groove formed onthe portion 68 of the piston rod 64 and forms a seal with the annularpiston 59 to prevent leakage of fluid under pressure between thechambers 62 and 63.

A brake release spring 74 is interposed between the pressure head 25 andthe right-hand side of the larger piston 15 to normally bias this piston15, and also the smaller piston 59, to the release position shown inFIG. 2 in which position the cup-shaped nut 67 is biased against theright-hand end of an annular boss 75 that is formed integral with theright-hand end of the cylinder body 50.

In order to provide for the supply of fluid under pressure to thechamber 32 on the right-hand side of the larger piston 15 in a mannerhereinafter described, the cylindrical member 10 has formed on itsbottom a longitudinally-extending boss 76 through which extends apassageway 77 that at its right-hand end opens into this chamber 32, asshown in FIG. 2.

Likewise, in order to provide for the supply of fluid under pressure tothe chamber 63 on the right-hand side of the smaller piston 59 in amanner hereinafter described, the cylinder body 50 has formed on itsbottom a longitudinally-extending boss 78 through which extends apassageway 79 that at its right-hand end opens into this chamber 63.

As shown in FIGS. 1 and 2, a passageway 80 extends through the leg 3 ofthe pipe bracket 1 and the pressure head 18 and opens at its right-handend into the chamber 41 on the left-hand side of the larger piston 15.Also, a passageway 81 extends through this leg 3 and pressure head 18and opens at its right-hand end into the chamber 62 on the left-handside of the smaller piston 59.

The novel brake control valve 6, which is shown in outline in FIG. 1 ofthe drawings, is shown diagrammatically in section when the right-handedge of FIG. 3A is placed along side of the left-hand edge of FIG. 3B.This brake control valve device 6 shown in FIGS. 3A and 3B has asectionalized casing comprising an upper casing section 82, a centercasing section 83, a lower casing section 84, and a first annulardiaphragm 85 that has its outer periphery clamped between the casingsections 82 and 83, it being understood that the three casing sections82, 83 and 84 are secured together by any suitable means, such as, forexample, studs and nuts (not shown).

The inner periphery of the diaphragm 85 is operatively connected to thelower end of a guide stem 86 that extends through coaxial bores in apair of diaphragm follower plates 87 and 88 and is provided with screwthreads adjacent its lower end for receiving a nut 89 which serves, whentightened, to force the follower plate 88 against a shoulder 90 on thestem 86 and thus clamp the inner periphery of the diaphragm 85 betweenthese follower plates 87 and 88. The guide stem 86 is slidably mountedin a bottomed bore 91 provided therefor in the upper casing section 82,as shown in FIG. 3A.

As may be seen from FIG. 3A, the diaphragm 85 and follower plates 87 and88 cooperate with the casing sections 82 and 83 to form on therespective opposite sides of this diaphragm a pair of chambers 92 and93.

The chamber 92 is open to atmosphere via a passageway 94 that extendsthrough the casing sections 83 and 84 and past a dished circular shield95 (FIG. 3B).

The shield 95 is preferably formed of a resilient material, such asrubber, and is held in place, in which its outer periphery rests againstan inner cylindrical surface on an insect excluder device 96, by anysuitable means, such as, for example, a rivet 97 that extends through abore in this insect excluder device 96.

As shown in FIGS. 3A and 3B, opening into the chamber 93 above thediaphragm 85 is one end of a passageway 98 that extends through thecasing sections 82, 83 and 84 and at its other end opens into the upperend of a counterbore 99 that is coaxial with a bore 100 extendingthrough the lower casing section 84.

As shown in FIG. 3A of the drawings, the center casing section 83embodies therein below the diaphragm 85 and diaphragm follower plate 87,five poppet-type valves 101, 102, 103, 104 and 105.

The poppet-type valve 101 is disposed in a first counterbore 106 that iscoaxial with a bore 107 which extends from the upper end of thiscounterbore 106 through the center casing section 83 to the atmosphericchamber 92 below the diaphragm 85.

The poppet valve 101 has formed integral with the upper side thereof avalve stem 108 that extends through the bore 107 into the chamber 92. Aresilient disc 109 constructed of, for example, rubber, is bonded to thelower side of the valve 101, and a first spring 110 is interposedbetween this lower side of the valve 101 and a shoulder 111 formed on ahollow cylindrical valve seat member 112 that is slidably mounted in thecounterbore 106.

As shown in FIG. 3A, the hollow valve seat member 112 has an annularvalve seat 113 formed at its upper end and an out-turned flange 114formed at its lower end.

This out-turned flange 114 is disposed in a second counterbore 115 thatextends into the central casing section 83 from the lower end thereofand has a diameter that is greater than the diameter of theabove-mentioned counterbore 106 that is coaxial therewith. A secondspring 116 disposed in the counterbore 115 is interposed between theupper end of the lower casing section 84 and the out-turned flange 114to normally bias this flange 114 against a shoulder 117 formed at theupper end of the counterbore 115.

It will be noted from FIG. 3A that the length of the hollow cylindricalvalve seat member 112 is such that, when the spring 116 biases theout-turned flange 114 against the shoulder 117 and the spring 110 biasesthe upper side of the poppet valve 101 against an annular stop 118formed on the center casing section 83 at the lower end of the bore 107,the resilient disc 109 bonded to the lower side of the valve 101 will bedisposed above and out of seating engagement with the annular valve seat113 at the upper end of the hollow valve seat member 112.

Moreover, the upper end of the valve stem 108 of the valve 101 will bedisposed a short distance below the lower side of the diaphragm followerplate 87.

As shown in FIG. 3A, opening into the lower end of the counterbore 115is one end of a passageway 119 that extends through the lower casingsection 84 and at its other end opens at the hereinbefore-mentionedgasket face 9 which is formed on the lower side, as viewed in FIGS. 3Aand 3B, of the lower casing section 84 of the brake control valve device6. As shown in FIGS. 1 and 2, this other end of the passageway 119 is inalignment with the left-hand end of the hereinbefore-mentionedpassageway 80 in the leg 3 of the pipe bracket 1, which passageway 80opens into the chamber 41.

Referring to FIG. 3A of the drawings, it will be seen that one end of apassageway 120 opens at the wall surface of the counterbore 106 at alocation that is above the shoulder 111 on the valve seat member 112while the spring 116 biases the flange 114 on the lower end of thismember 112 against the shoulder 117 at the upper end of the counterbore115. This passageway 120 extends through the casing sections 83 and 84and at its other end opens at the gasket face 9. As shown in FIGS. 1 and2, this other end of the passageway 120 is in alignment with theleft-hand end of a passageway 121 that extends through the leg 3 of thepipe bracket 1 and the pressure head 18 and has its right-hand end inalignment with the left-hand end of the passageway 77.

From the foregoing, it is apparent that, while the valve 101 is unseatedfrom the valve seat 113, the chamber 41 at the left-hand side of thepiston 15 (FIG. 2) is connected to the chamber 32 at the right-hand sideof this piston via passageway 80, passageway 119 (FIGS. 1 and 3A),counterbore 115 (FIG. 3A), the interior of hollow valve seat member 112,past valve seat 113, counterbore 106, passageway 120 (FIGS. 3A and 1),passageway 121 (FIGS. 1 and 2) and passageway 77 (FIG. 2).

As shown in FIG. 3A, the poppet-type valve 102 is disposed in a thirdcounterbore 122 that is coaxial with a bore 123 which extends from theupper end of this counterbore 122 through the casing section 83 to thechamber 92.

The poppet valve 102 has formed integral with the upper side thereof avalve stem 124 that extends through the bore 123 into the chamber 92.The lower side of the valve 102 has a resilient disc 125 bonded theretoand an annular resilient member 126 is disposed about the stem 124 andbonded to the upper side of this valve 102.

A hollow cylindrical valve seat member 127 is slidably mounted in thecounterbore 122. This valve seat member 127 is identical in constructionand interchangeable with the valve seat member 112. Consequently, thecorresponding elements of this valve seat member 127 will bedistinguished from those of the member 112 by the addition of a prime(') to the numeral for each respective corresponding element of thisvalve seat member 127.

Consequently, a third spring 128 is interposed between the lower side ofthe valve 102 and the shoulder 111' on the valve seat member 127, and afourth spring 129, disposed in a counterbore 130 coaxial withcounterbore 122 and of larger diameter, is interposed between the upperend of the casing 84 and the out-turned flange 114'. Therefore, thespring 129 biases flange 114' against a shoulder 131 formed at the upperend of the counterbore 130. This enables the spring 128 to bias theannular resilient member 126 on the upper side of valve 102 against anannular valve seat 132 formed at the lower end of the bore 123 and theresilient disc 125 that is bonded to the lower side of the valve 102 outof seating engagement with the valve seat 113'. In this position of thevalve 102, the upper end of the valve stem 124 of this valve 102 will bedisposed the same distance below the lower side of the diaphragmfollower plate 87 as the upper end of the valve stem 108 of valve 101,and communication will be closed between the interior of the counterbore122 and a passageway 133 that opens at one end at the wall surface ofthe bore 123 in alignment with an elongated peripheral annular groove134 on the valve stem 124 and at the opposite end into the chamber 92that is open to atmosphere, as hereinbefore explained.

Opening into the lower end of the counterbore 130 is one end of a shortpassageway 135 that, as shown in FIG. 3A, extends through the casingsection 84 and at its opposite end opens into the passageway 119intermediate the ends thereof.

As further shown in FIG. 3A, one end of a passageway 136 opens at thewall surface of the counterbore 122 at a location that is above theshoulder 111' on the valve seat member 127 while the spring 129 biasesthe flange 114' against the shoulder 131. This passageway 136 extendsthrough the casing sections 83 and 84 and at its other end opens at thegasket face 9 where, as shown in FIGS. 1 and 2, it continues through theleg 3 of the pipe bracket 1 and has its right-hand end in alignment withthe left-hand end of the passageway 79.

From the foregoing, it is apparent that, while the valve 102 (FIG. 3A)is unseated from the valve seat 113' and seated on valve seat 132, thechamber 41 (FIG. 2) is connected to the chamber 63 via passageways 80,119 and 135 (FIG. 3A), counterbore 130, the interior of hollow valveseat member 127, past valve seat 113', counterbore 122, passageway 136and passageway 79.

The poppet-type valve 103 and a hollow cylindrical valve seat member 137are identical in construction and interchangeable with the valve 102 andvalve seat member 127. Consequently, the corresponding parts of thevalve 103 will be distinguished from those of the valve 102 by theaddition of a prime (') to the numeral for each respective correspondingelement of this valve 103.

Likewise, the corresponding parts of the valve seat member 137 will bedistinguished from those of the members 112 and 127 by the addition of adouble prime (") to the numeral for each respective correspondingelement of this valve seat member 137.

Accordingly, a fifth spring 138 is interposed between the lower side ofthe valve 103 and the shoulder 111" on the valve seat member 137 to seatthe annular resilient member 126' on an annular valve seat 139 formed atthe lower end of a bore 140 through which extends a valve stem 141 ofthe valve 103.

Likewise, a sixth spring 142 is interposed between flange 114" and theupper end of the casing 84 to normally bias this flange 114" against ashoulder 143 formed at the lower end of a counterbore 144 that iscoaxial with the bore 140 and a larger counterbore 145 in which isdisposed the spring 142.

As shown in FIG. 3A, one end of a passageway 146 opens at the wallsurface of the counterbore 145 intermediate the ends thereof and theother end opens into the passage 133 which is open to atmosphere.Therefore, the interior of the counterbore 145 is normally vented toatmosphere since the spring 138 maintains the annular resilient member126' seated on the valve seat 139 which prevents flow of fluid underpressure into the counterbores 144 and 145 from one end of a passageway147 that opens at the wall surface of the bore 140 opposite an elongatedperipheral annular groove 148 provided on the valve stem 141 of valve103. This passageway 147 extends through the casing sections 83 and 84and at its other end opens into the passageway 119 which is connected tothe chamber 41 (FIG. 2) via the pathway hereinbefore described.

As shown in FIG. 3A, one end of a passageway 149 opens at the wallsurface of the counterbore 144 at a location that is always above theshoulder 111" on the valve seat member 137. This passageway 149 extendsthrough the casing sections 83 and 84 and at its other end opens at thegasket face 9 in alignment with the hereinbefore-mentioned passageway81, as is shown in FIGS. 1 and 2.

Therefore, it is apparent from FIGS. 2, 3A and 3B that the chamber 62(FIG. 2) is normally open to atmosphere via passageways 81 and 149,counterbore 144 (FIG. 3A), hollow valve seat member 137, counterbore145, passageways 146 and 133, chamber 92, passageway 94 (FIG. 3B), lowerend of counterbore 99 and past resilient shield 95. So long as thechamber 62 is thus vented to atmosphere, the spring 74 is able tomaintain the pistons 15 and 59 and the hollow rod 34 in the brakerelease position in which they are shown in FIG. 2.

The poppet-type valve 104 (FIG. 3A) constitutes a quick service valvefor controlling flow of fluid under pressure from a brake pipe 150(FIG. 1) to the brake cylinder chamber 62 (FIG. 2) when a brakeapplication is effected. This valve 104 is disposed in a counterbore 151that is coaxial with a bore 152 in which is disposed a valve stem 153that is integral with the upper side of valve 104 and extends through anannular resilient member 154 that is bonded to the upper side of thisvalve 104. The valve stem 153 is provided at its lower end with anelongated peripheral annular groove 153' that, while the member 154 isunseated from an annular valve seat 155 formed at the lower end of thebore 152, establishes a communication between one end of a passageway156 that opens at the wall surface of the bore 152 and the interior ofthe counterbore 151. This passageway 156 extends through the casingsections 83 and 84 and at its other end opens at the gasket face 9 inalignment with a passageway 157 (FIG. 1) in the leg 3 of the pipebracket 1 to which passageway 157 the brake pipe 150 is connected.

As shown in FIG. 3A, formed at the lower end of the counterbore 151 isan annular valve seat 158 against which a check valve 159 is normallybiased by a seventh spring 160 that is disposed in a counterbore 161coaxial with the bore 152 and interposed between the lower side of thischeck valve 159 and the casing section 84.

As further shown in FIG. 3A, opening into the lower end of thecounterbore 161 via a choke 162 therein is one end of a passageway 163that extends through the casing section 84 and at its other end opensinto the hereinbefore-mentioned passageway 149 that is connected to thechamber 62 (FIG. 2) via the passageway 81.

It will be noted from FIG. 3A that an eighth spring 164 is disposed inthe counterbore 151 and interposed between the lower side of the valve104 and the upper side of the check valve 159. The strength of thisspring 164 is less than that of the spring 160 thereby enabling thespring 160 to normally seat the check valve 159 on its seat 158 and thespring 164 to seat the resilient member 154 secured to the upper side ofthe valve 104 on the annular valve seat 155 formed at the lower end ofthe bore 152.

When the resilient member 154 secured to the upper side of the valve 104is unseated from the valve seat 155 by the diaphragm follower plate 87shifting the valve stem 153 downward, in a manner hereinafter explained,the strength of the spring 160 is such as to enable flow of fluid underpressure from the brake pipe 1 to the chamber 62 (FIG. 2) on theleft-hand side of the piston 59 until the pressure in this chamber 62and the interior of the counterbore 161 is increased to a chosen value.

Finally, the poppet-type valve 105 constitutes a charging valve 165 toenable charging of the chambers 41 and 32 (FIG. 2) in the novel brakecylinder device 7 from the brake pipe 150. This poppet valve 105 (FIG.3A) has a resilient disc 166 bonded to its lower side and a valve stem167 extending from its upper side through a bore 168 in the casingsection 83 into the chamber 92. This bore 168 opens at its lower endinto a coaxial counterbore 169 that in turn at its lower end opens intoa coaxial counterbore 170 of larger diameter.

A hollow cylindrical valve seat member 171 that is identical with thevalve seat members 112, 127 and 137 is slidably mounted in thecounterbore 169. Consequently, the corresponding elements of this valveseat member 171 will be distinguished from those of the members 112, 127and 137 by the addition of a triple prime ('") to the numeral for eachrespective corresponding element of this valve seat member 171.

Accordingly, a nineth spring 172 is interposed between the lower side ofthe poppet valve 105 and the shoulder 111'" on the valve seat member 171and a tenth spring 173, which is stronger than the spring 172, isinterposed between the out-turned flange 114'" on the lower end of thisvalve seat member 171 and a check valve 174 that is disposed in thecounterbore 170 and has a small passageway extending therethrough whichconstitutes a charging choke 175. Therefore, this stronger spring 173normally biases the check valve 174 against an annular valve seat 176formed on the lower casing section 84 while the weaker spring 172 biasesthe poppet valve 105 against an annular stop 177 formed on the casingsection 83 at the lower end of the bore 168 therein.

As shown in FIG. 3A, opening within the annular valve seat 176 is oneend of a short passageway 178 that extends through the casing section 84and opens at its other end into the passageway 119 at the junction ofthe passageway 147 with this passageway 119.

As is also shown in FIG. 3A, one end of a passageway 179 opens at thewall surface of the counterbore 169 at a location that is always abovethe shoulder 111'" on the valve seat member 171. This passageway 179extends through the casing section 83 and at its other end opens intothe hereinbefore-mentioned passageway 156 intermediate the ends thereof.

In order to normally bias the diaphragm follower plate 87 out ofengagement with the upper end of the valve stems 108, 124, 141, 153 and167, a spring 180 is interposed between the lower side of this followerplate 87 and the casing section 83.

Furthermore, each of the valve stems 108, 141, 153 and 167 is providedintermediate its ends with a peripheral annular groove in which isdisposed an O-ring seal 181 that forms a seal with the wall surface ofthe respective bore in which these valve stems are disposed to preventleakage of fluid under pressure into the chamber 92 that is open toatmosphere, as hereinbefore explained.

Moreover, each of the valve seat members 112, 127, 137 and 171 isprovided intermediate its ends with a peripheral annular groove in whichis disposed an O-ring seal 182 that forms a seal with the wall surfaceof the respective counterbore in which these valve seat members areslidably disposed to prevent leakage of fluid under pressure between theperipheral surface of these valve seat members and the wall surface ofthe respective counterbore.

As shown in FIG. 3B of the drawings, the novel brake control valvedevice 6 further comprises an application and release control valvemechanism 183 that is embodied in the hereinbefore-mentioned casingsections 82, 83 and 84.

The application and release control valve mechanism 183 comprises afirst annular diaphragm 184 that has its outer periphery clamped betweenthe casing sections 82 and 83.

The inner periphery of the diaphragm 184 is operatively connected to theupper end of a stem 185 that is fluted for a chosen distance from itslower end. Above this fluted portion, the stem 185 is provided with aperipheral annular groove in which is disposed an O-ring seal 186 thatforms a seal with the wall surface of a bore 187 that extends throughthe center casing section 83. This stem 185 is further provided with ashoulder 188 against which rests a first diaphragm follower plate 189and external screw threads for receiving a nut 190 which serves, whentightened, to force the follower plate 189 against the shoulder 188 andclamp the inner periphery of the diaphragm 184 between this plate 189and a second follower plate 191.

As may be seen from FIG. 3B, the diaphragm 184 and follower plates 189and 191 cooperate with the casing sections 82 and 83 to form on therespective opposite sides of this diaphragm a pair of chambers 192 and193.

Opening into the chamber 192 is one end of a passageway 194 that extendsthrough the casing sections 82 and 83 and at its opposite end opens intothe passageway 147 intermediate the ends thereof.

Opening into the chamber 193 is one end of a passageway 195 that extendsthrough the casing sections 83 and 84 and at its opposite end opens intothe passageway 156 intermediate the ends thereof.

As shown in FIG. 3B, a bore 196 disposed in parallel spaced-apartrelationship to the bore 187 extends into the casing section 83 from thechamber 193 and has an annular valve seat 197 formed at its lower end. Abore 198 that is coaxial with and of larger diameter than the bore 196has a spring seat 199 pressed thereinto. This spring seat 199 isprovided with a peripheral annular groove thereon in which is disposedan O-ring seal 200 to prevent leakage of fluid under pressure from achamber 201 above this spring seat. This chamber 201 is connected to thepassageway 147 by a short passageway 202 and has disposed therein apoppet-type valve 203.

The poppet-type valve 203 has formed integral with one side thereof avalve stem 204 that extends through the bore 196 into the chamber 193.This stem 204 is provided adjacent the valve 203 with an elongatedperipheral annular groove 205 above which is a peripheral annular groovethat has an O-ring seal 206 disposed therein to form a seal with thewall surface of the bore 196 and thereby prevent leakage of fluid underpressure between the chambers 193 and 201. A resilient annular member207 constructed of, for example, rubber, is disposed about the stem 204and bonded to the upper side of the valve 203. The spring 208 interposedbetween the spring seat 199 and the lower side of the valve 203 normallybiases the annular member 207 against the valve seat 197 to closecommunication between the chamber 201 and one end of a passageway 209that opens at the wall surface of the bore 196 at a location inalignment with the groove 205 on the stem 204. This passageway 209extends through the casing section 83 and at its other end opens intothe passageway 98 intermediate the ends thereof.

As shown in FIG. 3B, the upper casing section 82 is provided with abottomed bore 210 and two coaxial counterbores 211 and 212. A hollowcylindrical valve member 213 having a spring 214 disposed thereabout onthe upper side of a collar 215 integral therewith is slidably mounted inthe bottomed bore 210 after which a bushing 216 having an annular valveseat 217 on its upper end is pressed into the counterbore 211 until aport 218 in this bushing is in alignment with that end of a passageway219 that opens at the wall surface of the counterbore 211. Thispassageway 219 extends through the casing section 82 and at its otherend opens into the passageway 98 intermediate the ends thereof. Aresilient annular member 220 is bonded to the lower side of the collar215 and is normally biased against the annular valve seat 217 by thespring 214 interposed between the upper side of the collar 215 and theupper end of the larger counterbore 211 to close communication betweenthe passageway 219 and a passageway 221 that at one end opens at thewall surface of the counterbore 211 and at the other end into thepassageway 94 intermediate the ends thereof.

As shown in FIG. 3B, the cylindrical valve member 213 is providedadjacent each of its opposite ends with a peripheral annular groove ineach of which is disposed an O-ring seal 222. The upper O-ring seal 222forms a seal with the wall surface of the bottomed bore 210 and thelower O-ring seal 222 forms a seal with the wall surface of the bushing216.

As further shown in FIG. 3B, the valve member 213 is provided below theresilient member 220 with an elongated peripheral annular groove 223through which fluid under pressure flows from the passageway 219 to thepassageway 221 when the member 220 is unseated from the valve seat 217in a manner hereinafter explained.

The application and release control valve mechanism 183 shown in FIG. 3Bof the drawings further comprises a second annular diaphragm 224 thathas its outer periphery clamped between the casing sections 83 and 84.This diaphragm 224 is connected to a valve mechanism for releasing fluidunder pressure from the chamber 32 (FIG. 2) in the brake cylinder device7 to atmosphere to cause the fluid under pressure present in thechambers 62 and 41 and acting respectively on the left-hand side of thepistons 59 and 15 to increase the braking force pressing the brake shoesagainst the tread surface of the wheels of the vehicle in accordancewith the degree of reduction of the pressure in the chamber 32.

As shown in FIG. 3B, extending into the casing section 83 from the lowerend thereof is a counterbore 225 that is coaxial with thehereinbefore-mentioned bore 187 into the upper end of which counterbore225 extends the fluted portion of the valve stem 185.

In assembling the application and release control valve mechanism 183, aspring 226 is first placed in the counterbore 225 after which a hollowcylindrical exhaust valve seat member 227 is inserted into thiscounterbore 225 so that an out-turned flange 228 integral with the upperend, as viewed in FIG. 3B, of this valve seat member 227 abuts the lowerend of the spring 226. This exhaust valve seat member 227 is provided atits lower end with an annular exhaust valve seat 229 and intermediateits ends with a peripheral annular groove in which is disposed an O-ringseal 230 that forms a seal with the wall surface of a bushing 231 thatis next pressed into the counterbore 225 from the lower end thereof. Asshown in FIG. 3B, the interior wall surface of the bushing 231intermediate the ends thereof has formed therein, as by a machiningoperation, an elongated annular groove 232, it being noted that thelower end of the exhaust valve seat member 227 on which is formed theexhaust valve seat 229 terminates between the upper and lower ends ofthis groove 232.

While the parts of the application and release control valve mechanism183 occupy the position shown in FIG. 3B of the drawings, the exhaustvalve seat 229 abuts a resilient annular member 233 that is bonded tothe upper end of a fluted valve stem 234 slidably mounted in the bushing231 so that this end of the stem 234 and the resilient annular member233 constitute an exhaust valve that when seated on the seat 229 closescommunication between the lower and upper ends of the counterbore 225.

It will be noted that, while the exhaust valve seat member 227 occupiesthe position shown in FIG. 3B, the lower side of the out-turned flange228 is disposed a short distance above the upper end of the bushing 231and the upper side of this flange is disposed below that end of apassageway 235 that opens at the wall surface of the counterbore 225.This passageway 235 extends through the casing sections 83 and 84 and atits other end opens at the wall surface of the hereinbefore-mentionedcounterbore 99 in the casing section 84 above the shield 95.

As shown in FIG. 3B, adjacent its lower end, the stem 234 is providedwith a shoulder 236 against which rests a first diaphragm follower plate237 and external screw threads for receiving a nut 238. This nut 238serves, when tightened, to force the follower plate 237 against theshoulder 236 and clamp the inner periphery of the diaphragm 224 betweenthis plate 237 and a second follower plate 239.

Consequently, the diaphragm 234 and follower plates 237 and 239cooperate with the casing sections 83 and 84 to form on the respectiveopposite sides of this diaphragm 234 a pair of chambers 240 and 241.

Opening into the chamber 240 is one end of a passageway 242 that extendsthrough the casing sections 83 and 84 and at its other end, as shown inFIG. 3A, opens into the hereinbefore-mentioned passageway 120.

Opening into the chamber 241 (FIG. 3B) is one end of a short passageway243 that extends through the casing section 84 and at its other endopens into the hereinbefore-mentioned passageway 195.

As shown in FIG. 3B, a piston rod 244 that is slidably mounted in thebore 100 has a collar 245 formed thereon to enable a cup-shaped piston246 that is slidable in the counterbore 99 to be operatively connectedto this piston rod 244 by a snap ring 247. A spring 248 interposedbetween the piston 246 and the insect excluder device 96 biases thecollar 245 against a stop 249 formed on the casing section 84 at thelower end of the bore 100. This spring 248 is stronger than the spring226. Accordingly, these two springs 226 and 248 bias the diaphragm 224,diaphragm follower plates 237 and 239, stems 234 and 244 and hollowcylindrical exhaust valve seat member 227 to the position shown in FIG.3B in which the upper end of the piston rod 244 abuts the nut 238, theout-turned flange 228 is disposed above the upper end of the bushing231, and the collar 245 abuts the stop 249.

A third spring 250 that is interposed between the diaphragm followerplate 191 and the upper end of the counterbore 212 is effective to biasthe diaphragm 184, diaphragm follower plates 191 and 189, and stem 185to the position shown in FIG. 3B, it being understood that the spring248 is stronger than the two springs 250 and 226 combined.

As shown in FIG. 3B, the piston rod 244 intermediate its ends isprovided with a peripheral annular groove in which is disposed an O-ringseal 251 that forms a seal with the wall surface of the bore 100 toprevent leakage of fluid under pressure from the chamber 241 to the topof the piston 246. This piston 246 is provided with a peripheral annulargroove in which is disposed an O-ring seal 252 that forms a seal withthe wall surface of the counterbore 99 to prevent leakage of fluid underpressure from the passageway 98 to atmosphere past the shield 95.

Furthermore, an O-ring seal 253 is disposed about the piston rod 244 andinterposed between the piston 246 and the snap ring 247 to preventleakage of fluid under pressure from the top of the piston 246 toatmosphere.

OPERATION Initial Charging

Let it be assumed that the leg 2 (FIG. 1) of the pipe bracket 1 issecured to the body of a railway freight car so that this car isprovided with the novel brake control valve device 6 (FIGS. 1A and 1B)and brake cylinder device 7 (FIG. 2) that constitute the presentinvention.

Furthermore, assume that this freight car has been coupled into a trainof cars, and that a handle of an engineer's brake valve device (notshown) located on the locomotive coupled to the head end of the train isin its release position. Therefore, while the handle of the brake valvedevice is in its release position, this brake valve device will effectthe supply of fluid under pressure to the train brake pipe and,therefore, to the brake pipe 150 (FIG. 1) to charge the train brake pipeto a preselected normal charged value which, for example, may be seventypounds per square inch.

Fluid under pressure thus supplied to the brake pipe 150 will flow viapassageway 157, passageway 156 (FIG. 3A) and passageway 179 to theinterior of the counterbore 169.

Since the resilient disc 166 of poppet valve 105 is unseated from valveseat 113'" by the spring 172 thus opening charging valve 165, fluidunder pressure will flow from the interior of the counterbore 169 to thepassageway 178 via the hollow valve seat member 171, counterbore 170 andchoke 175 at a rate determined by the size of this choke 175.

Fluid under pressure supplied to the passageway 178 will flow to: (1)the chamber 41 (FIG. 2) in the brake cylinder device 7 via passageways119 and 80, (2) the chamber 32 in this brake cylinder device 7 viapassageway 119 (FIG. 3A), counterbore 115, hollow valve seat member 112,past valve seat 113, since disc 109 of valve 101 is unseated therefromby spring 110, counterbore 106, and passageways 120, 121 (FIG. 1) and 77(FIG. 2), (3) the chamber 63 in brake cylinder device 7 via passageways119 (FIG. 3A) and 135, counterbore 130, hollow valve seat member 127,past valve seat 113', since disc 125 of valve 102 is unseated therefromby spring 128, counterbore 122, and passageways 136 and 79 (FIG. 2), (4)groove 148 (FIG. 3A) on valve stem 141 of valve 103, which is seated onseat 139 by spring 138, via passageway 147, (5) chamber 192 (FIG. 3B)via passageways 147 and 194, and (6) chamber 201 via passageways 147 and202.

Furthermore, some of the fluid under pressure that is supplied from thebrake pipe 150 to the passageway 156 (FIG. 3A) flows therefrom to: (1)groove 153' on valve stem 153 of valve 104 which is seated on seat 155by spring 164, (2) chamber 193 (FIG. 3B) via passageway 195, and (3)chamber 241 via passageways 195 and 243.

Moreover, it will be noted from FIGS. 3A and 3B that some of the fluidunder pressure supplied to the passageway 120 flows to the chamber 240via the passageway 242.

From the foregoing, it is apparent that the chambers 41 (FIG. 2), 32 and63 in the brake cylinder device 7, the chambers 192 and 193 (FIG. 3B) onthe respective opposite sides of the diaphragm 184 and the chambers 240and 241 on the respective opposite sides of the diaphragm 224 are allcharged to the normal charged value of the train brake pipe which maybe, as hereinbefore stated, seventy pounds per square inch.

With the chambers 191, 193, 240 and 241 all charged to the pressurecarried in the train brake pipe, the springs 250, 226 and 248 areeffective to shift the diaphragms 184 and 224, stems 185 and 234,exhaust valve seat member 227, piston rod 244 and piston 246 to theposition shown in FIG. 3B.

It will be noted from FIGS. 1, 2, 3A and 3B that the chamber 62 in thebrake cylinder device 7 is open to atmosphere via passageways 81 and149, counterbore 144, hollow cylindrical valve seat member 137,counterbore 145, passageways 146 and 133, chamber 92, passageway 94,lower end of counterbore 99 and past shield 95 of the insect excluderdevice 96.

Therefore, with the chambers 41, 32 and 63 charged to the pressurecarried in the train brake pipe and the chamber 62 open to atmosphere,the brake release spring 74 is effective to shift the pistons 15 and 59to the brake release position in which they are shown in FIG. 2. Whilein this position, the cup-shaped nut 67 abuts the end of the annularboss 75 on the right-hand end of the brake cylinder body 50.

Brake Application

A brake application is initiated by effecting a reduction of thepressure in the brake pipe 150 (FIG. 1) by the engineer moving thehandle of the engineer's brake valve device on the locomotive to achosen position in its application zone in the usual well-known manner.

As the pressure in the brake pipe 150 is reduced, the pressure in thechamber 193 (FIG. 3B) below the diaphragm 184 and in the chamber 241below the diaphragm 224 will be correspondingly reduced.

Since fluid under pressure cannot flow from the chambers 192 and 240 tothe brake pipe 150 via the choke 175 in the check valve 174 as fast asfluid under pressure is flowing from the chambers 193 and 241 to thebrake pipe 150 via passageways 243, 195, 156 and 157 (FIG. 1) in whichthere are no chokes, it is apparent that a differential fluid pressureforce is quickly established that acts in a downward direction todeflect diaphragms 184 (FIG. 3B) and 224 downward and thereby effectshifting of diaphragm follower plates 189, 191, 237 and 239 downward.

As the diaphragm follower plate 189 is thus shifted downward, it willfirst abut the upper end of valve stem 204 of valve 203 and thereaftershift this stem downward to unseat annular member 207 of this valve 203from its seat 197.

Upon the unseating of annular member 207 of valve 203 from its seat 197,fluid under pressure will flow from the chamber 41 (FIG. 2) in the brakecylinder device 7 to the chamber 93 (FIG. 3A) above diaphragm 85 viapassageway 80 (FIGS. 1 and 2), passageways 119, 147 and 202 (FIGS. 3Aand 3B), chamber 201, past valve seat 197, bore 196 and passageways 209and 98.

Some of the fluid under pressure supplied to the passageway 98 flows tothe upper side of the cup-shaped piston 246 to shift this piston and thepiston rod 244 downward against the yielding resistance of the spring248 so that the upward bias of this spring 248 is removed from thediaphragms 184 and 244.

Moreover, fluid under pressure will flow from the chamber 192 to thechamber 93 via passageways 194, 147 and 202, and the pathway describedabove.

Fluid under pressure thus supplied to the chamber 93 establishes a fluidpressure force which will deflect the diaphragm 85 downward against theyielding resistance of the spring 180.

As the diaphragm 85 is thus deflected downward, the diaphragm followerplates 87 and 88 are shifted downward whereupon the follower plate 87will first abut the upper end of the valve stems 108, 124, 141, 153 and167 and thereafter shift these stems downward simultaneously.

As the stem 108 is thus shifted downward, the valve 101 and disc 109 areshifted downward against the yielding resistance of the spring 110 toeffect seating of this disc 109 on the valve seat 113 to thereby closecommunication between chambers 41 (FIG. 2) and 32 in the brake cylinderdevice 7.

As the valve stem 124 is thus shifted downward, the valve 102 togetherwith disc 125 and resilient member 126 bonded thereto are shifteddownward against the yielding resistance of the spring 128 to firstunseat member 126 from valve seat 132 and thereafter seat disc 125 onvalve seat 113'.

The seating of the disc 125 on the valve seat 113' closes communicationbetween the chambers 41 and 63 (FIG. 2) in the brake cylinder device 7.

Upon the unseating of the member 126 (FIG. 3A) from the seat 132, thefluid under pressure in the chamber 63 (FIG. 2) is vented to atmospherevia passageway 79 (FIG. 2), passageway 136 (FIGS. 1 and 3A), counterbore122, past valve seat 132, bore 123, passageway 133, chamber 92,passageway 94 (FIG. 3B), lower end of counterbore 99 and past shield 95of insect excluder device 96.

As the valve stem 141 is shifted downward, the valve 103 together withdisc 125' and member 126' bonded thereto are shifted downward againstthe yielding resistance of spring 138 to first unseat member 126' fromvalve seat 139 and thereafter seat disc 125' on valve seat 113".

The seating of the disc 125' on the seat 113" closes communicationbetween the chamber 62 (FIG. 2) in the brake cylinder device 7 andatmosphere.

Upon the unseating of the member 126' from the seat 139, fluid underpressure will flow from the chamber 41 (FIG. 2) to the chamber 62 in thebrake cylinder device 7 via the passageway 80 (FIGS. 1 and 2),passageway 119 (FIG. 3A), passageway 147 (FIGS. 3A and 3B), bore 140,past valve seat 139, counterbore 144, passageway 149 and passageway 81(FIG. 1).

As the valve stem 153 (FIG. 3A) is shifted downward, the valve 104 andmember 154 bonded thereto are shifted downward against the yieldingresistance of the spring 164 and away from the valve seat 155, whereuponfluid under pressure will flow from the brake pipe 150 (FIG. 1) to thechamber 62 (FIG. 2) via passageway 157 (FIG. 1), passageway 156 (FIG.3A), bore 152, past valve seat 155, counterbore 151, past check valve159 which is unseated from its seat 158 against the yielding resistanceof the spring 160 by the fluid under pressure supplied to thecounterbore 151, counterbore 161, choke 162, passageways 163 and 149,and passageway 81 (FIGS. 1 and 2).

As the valve stem 167 (FIG. 3A) is shifted downward, the charging valve165 and disc 166 bonded thereto are shifted downward against theyielding resistance of the spring 172 to effect seating of the disc 166on the valve seat 113'".

This seating of disc 166 on valve seat 113'" prevents back flow from thechamber 41 (FIG. 2) in the brake cylinder device 7 and chamber 192 (FIG.3B) in the brake control valve device 6 to the brake pipe 150 (FIG. 1)from which brake pipe fluid under pressure is being released toatmosphere via the engineer's brake valve device on the locomotive.

Fluid under pressure will now flow from the chambers 41 and 32 (FIG. 2)in the brake cylinder device 7 and from the brake pipe 150 (FIG. 1) tothe chamber 62 (FIG. 2) until equalization of the pressures in thesechambers occurs. The equalization pressure thus obtained can be bestillustrated by way of a specific example.

Accordingly, it will be assumed that:

(1) The diameter of piston 59 is 3.625 inches.

(2) The diameter of piston 15 is 14.0 inches.

(3) The diameter of piston rod 64 is 1.0 inches.

(4) The diameter of hollow rod 34 is 3.0 inches.

(5) The pistons 59 and 15 are shifted in the direction of the righthand, as viewed in FIG. 2, a distance of 4.0 inches by the fluid underpressure supplied to the chamber 62 at the left-hand side of the piston59 in order to, via the brake rigging (not shown), bring the brakingsurfaces of the brake shoes (not shown) into braking contact with thetread surface of the wheels of the vehicle. Therefore, the increase involume of the chamber 62 may be calculated as follows:

Area of a 3.625 inch diameter piston=

    (3.1416×(3.625).sup.2)/4=10.321 square inches

Then increase in volume of chamber 62=10.321 square inches×4inches=41.284 cubic inches.

(6) The volume of chamber 41 is 320 cubic inches, while the pistons 15and 59 occupy the release position shown in FIG. 2.

(7) The volume of chamber 32 is 880 cubic inches, while the pistons 15and 59 occupy the release position shown in FIG. 2.

(8) The volume of chamber 62 (while piston 59 occupies the positionshown in FIG. 2) and the passageways 81 and 149 is 10 cubic inches.

(9) A volume of fluid under pressure equal to the volume of a 11/4 inchdiameter pipe 50 feet long flows from the brake pipe 150 (FIG. 1) pastthe check valve 159 (FIG. 3A) and through the choke 162 to the chamber62 (FIG. 2). It can be shown mathematically that the volume of fluidunder pressure in this 50 feet of brake pipe is 736.32 cubic inches.

(10) The pressure in the brake pipe 150 (FIG. 1) when fully charged is70 pounds per square inch gage or 84.7 pounds per square inch absolutepressure.

It should be noted that when fluid under pressure flows from the chamber41 (FIG. 2) to the chamber 62, this reduces the pressure in the chamber41 whereupon the one-way valve 42 will be unseated from the annular bead39 so that fluid under pressure will flow from the chamber 32 to thechamber 41. Therefore, the fluid under pressure from both of thesechambers 32 and 41 will equalize into the chamber 62. Accordingly, thecombined volume of these two chambers 41 and 32 that equalize into thechamber 62 is 320 cubic inches plus 880 cubic inches which is a total of1200 cubic inches.

Now, if the equalization pressure be denoted by P₂, then this pressurecan be calculated from the following mathematical equation:

    1200 cubic inches×84.7 pounds per square inch+736.32 cubic inches×84.7 pounds per square inch+10 cubic inches×14.7 pounds per square inch=1200 cubic inches×P.sub.2 +736.32 cubic inches×P.sub.2 +10 cubic inches×P.sub.2 +41.284 cubic inches×P.sub.2.

Then:

P₂ =82.5 pounds per square inch absolute pressure, or

P₂ =82.5-14.7=67.8 pounds per square inch gage.

Now, to calculate the braking force for pressing the brake shoes againstthe tread surface of the wheels, assume that:

(1) Ratio of the brake rigging is 2.

(2) The strength of release spring 74 after the piston 15 moves 4 inchesin the direction of the right hand is 400 pounds.

Then:

(a) 10.321 square inches×67.8 pounds per square inch=700 pounds=Forceacting in the direction of the right hand on the left-hand side ofpiston 59 (FIG. 2).

(b) The diameter of the piston 15 is 14.0 inches, as hereinbeforestated. Therefore, the area of a 14.0 diameter piston is:(3.1416×(14)²)/4=153.94 square inches. The diameter of piston rod 64 is1.0 inch, as hereinbefore stated. Therefore, the area of a 1 inchdiameter piston rod is (3.1416×(1)²)/4=0.7854 square inch.

Then:

153.94 square inches-0.7854 square inches=152.1546 square inches=Area ofpiston 15 that is subject to the pressure of the fluid in chamber 41(FIG. 2).

Then:

152.1546 square inches×67.8 pounds per square inch=10,320 pounds=Forceacting in the direction of the right hand on the left-hand side of thepiston 15 (FIG. 2).

(c) The diameter of the hollow rod 34 is 3.0 inches.

Therefore, the area of a 3.0 inch rod is:

    (3.1416×(3).sup.2)/4=7.0686 square inches.

Then:

153.94 square inches-7.0686 square inches=146.8714 square inches=Area ofpiston 15 that is subject to the pressure of the fluid in chamber 32(FIG. 2).

Therefore:

146.8714 square inches×67.8 pounds per square inch=9,950 pounds=Forceacting in the direction of the left hand on the right-hand side ofpiston 15.

Accordingly, the net force acting in the direction of the right hand onpistons 59 and 15 is:

    700 pounds+10,320 pounds-9,950 pounds-400 pounds=670 pounds.

Since it has been assumed that the braking ratio is 2, then, the forcepressing the brake shoes against the tread surface of the wheels of thevehicle is:

    670 pounds×2=1,340 pounds.

From the foregoing, it is apparent that subsequent to movement of thepistons 59 (FIG. 2) and 15 a distance of 4 inches and equalization ofthe pressure of the fluid in the chambers 32 and 41 into the chamber 62at the above-mentioned pressure of 67.8 pounds per square inch, and alsothe equalization of the pressure of the fluid in the assumed 50 feet oftrain brake pipe into this chamber 62, the force pressing the brakeshoes against the tread surface of the vehicle wheels is 1,340 pounds.

As the piston 15 moves 4 inches in the direction of the right hand fromthe position shown in FIG. 2, the decrease in the volume of the chamber32 may be calculated as follows:

    146.8714 square inches×4 inches=587.4856 cubic inches.

Therefore, the volume of chamber 32 subsequent to the pistons 59 and 15moving in the direction of the right hand, as viewed in FIG. 3, adistance of 4 inches is:

    880.0 cubic inches-587.4856 cubic inches=292.5144 cubic inches.

Moreover, the pressure in the chambers 41, 32 and 62 in the brakecylinder device 7 (FIG. 2) is now the equalized pressure of 67.8 poundsper square inch gage.

Since the handle of the engineer's brake valve device on the locomotivehas been moved to a position in its application zone, the relay valvedevice of this brake valve device, which may be the same as that shownand described in U.S. Pat. No. 2,958,561, issued Nov. 1, 1960 to HarryC. May, and assigned to the assignee of the present application, willcontinue to vent fluid under pressure from the brake pipe 150 (FIG. 1)to atmosphere.

As fluid under pressure is thus released from the brake pipe 150(FIG. 1) to atmosphere to effect a reduction of the pressure of thefluid therein, a corresponding reduction of the pressure of the fluid inthe chambers 193 and 241 (FIG. 3B) in the brake control valve device 6will continue.

Consequently, it is apparent from FIG. 3B that as the pressure of thefluid in the chambers 193 and 241 continues to be reduced, the pressureof the fluid in the chambers 192 and 240, which pressure is thehereinbefore-mentioned equalized pressure of 67.8 pounds per square inchgage, will continue to deflect the diaphragms 184 and 224 downward sothat as the valve stems 185, 234 and 204 are simultaneously shifteddownward thereby, the spring 226 is rendered effective to simultaneouslyshift exhaust valve seat member 227 downward until the out-turned flange228 integral therewith abuts a stop 254 formed by the upper end of thebushing 231.

Subsequent to the movement of the flange 228 into abutting engagementwith the stop 254, the continued downward shifting of the valve stems185, 204 and 234 by the diaphragms 184 and 224 will unseat the resilientannular member 233 that is bonded to the upper end of the fluted valvestem 234 from the exhaust valve seat 229 at the lower end of the exhaustvalve seat member 227.

When annular member 233 is thus unseated from the exhaust valve seat229, fluid under pressure will flow from the chamber 32 (FIG. 2) in thebrake cylinder device 7 and the chamber 240 (FIG. 3B) in the brakecontrol valve device 6 to atmosphere via passageway 77 (FIG. 2),passageway 121 (FIGS. 1 and 2), passageways 120 and 242 (FIGS. 3A and3B), chamber 240 above diaphragm 224 (FIG. 3B), between the interior ofbushing 231 and the fluted stem 234, groove 232 in this bushing 231,past valve seat 229, between the interior of exhaust valve seat member227 and the fluted portion of stem 185, counterbore 225, passageway 235,lower end of counterbore 99 and past shield 95 of insect excluder device96.

Fluid under pressure will thus flow from the chamber 32 (FIG. 2) andchamber 240 (FIG. 3B) to atmosphere until the self-lapping relay valvedevice of the engineer's brake valve device on the locomotive reducesthe pressure of the fluid in the brake pipe 150 (FIG. 1) and thechambers 193 and 241 (FIG. 3B) to a value corresponding to the positionin its application zone to which the handle of this brake valve devicehas been moved by the engineer.

Upon the self-lapping relay valve device of the engineer's brake valvedevice terminating the release of fluid under pressure from the brakepipe 150 (FIG. 1) and chambers 241 and 193 (FIG. 3B), the continued flowof fluid under pressure from the chamber 32 (FIG. 2) in the brakecylinder device 7 and the chamber 240 (FIG. 3B) in the brake controlvalve device 6 to atmosphere will establish a differential fluidpressure force which acts in an upward direction on the diaphragm 224.

Accordingly, as this differential fluid pressure force acting in anupward direction on the diaphragm 224 increases, it will deflect thisdiaphragm 224 upward to shift the fluted stems 234 and 185 upward untilthe annular member 233 abuts the exhaust valve seat 229 therebyterminating the release of fluid under pressure from the chamber 32(FIG. 2) and chamber 240 (FIG. 3B).

As the stem 185 is thus shifted upward, it will shift the diaphragmfollower plates 189 and 191 upward. As the diaphragm follower plate 189is thus shifted upward, the spring 208 is rendered effective to shiftvalve 203, valve stem 204 and annular member 207 upward toward the valveseat 197. It should be noted, however, that the length of the valvestems 185, 204 and 234 are such that the annular member 233 is shiftedupward into abutting relationship with the exhaust valve seat 229 beforethe annular member 207 bonded to the valve 203 is seated on the valveseat 197 by the spring 208. Consequently, the supply of fluid underpressure from the chamber 192 (FIG. 3B) and chamber 41 (FIG. 2) to thechamber N&42IG. 3A) is maintained so that the diaphragm 85 is effectivevia diaphragm follower plate 87 and valve stems 108, 124, 141, 152 and167 to hold the valves 101, 102, 103, 104 and 105 in their lowerposition.

From the foregoing, it is apparent that subsequent to the pistons 59(FIG. 2) and 15 shifting the above-mentioned assumed distance of 4.0inches to bring the braking surface of the brake shoes into brakingcontact with the tread surface of the vehicle wheels and press theseshoes against the thread surface of these wheels with the afore-statedforce of 1,340 pounds, the brake control valve device 6 is operative inresponse to the continued release of fluid under pressure from the trainbrake pipe by the relay valve device of the engineer's brake valvedevice on the locomotive to release fluid under pressure from thechamber 32 (FIG. 2) to atmosphere to further increase the force pressingthe brake shoes against the tread surface of the vehicle wheels.

Accordingly, let it be assumed that the engineer on the locomotive movedthe handle of the engineer's brake valve device to its full serviceposition. Upon movement of this handle to its full service position, therelay valve device of this engineer's brake valve device will operate torelease fluid under pressure from the brake pipe 150 (FIG. 1) and thechambers 193 and 241 (FIG. 3B) to atmosphere, in the manner explained inthe above-mentioned U.S. Pat. No. 2,958,561, until the pressure in thispipe and these chambers is reduced to 50 pounds per square inch.

When the pressure in the chambers 193 and 240 is reduced to 50 poundsper square inch, the brake control valve device 6 operates in responsethereto to release fluid under pressure from the chamber 240 in thisbrake control valve device 6 and the chamber 32 (FIG. 2) in the brakecylinder device 7 to atmosphere until the pressure in these chambers 240and 32 is correspondingly reduced to 50 pounds per square inch.

It will be noted that the one-way valve device 42 (FIG. 2) prevents flowfrom the chamber 41 to the chamber 32. Consequently, the pressure in thechamber 41 (FIG. 2) and chamber 192 (FIG. 3B) remains at theafore-mentioned equalized pressure of 67.8 pounds per square inch.

In order that a freight car provided with the novel brake control valvedevice 6 and the novel brake cylinder device 7, that constitute thepresent invention, operates satisfactorily in a train of cars, one ormore of which cars are provided with the brake equipment disclosed inhereinbefore-mentioned U.S. Pat. Nos. 3,175,869 and 3,183,795, let itnow be assumed that:

(1) The effective area of the diaphragm 224 is one square inch, andthat:

(2) The effective area of the diaphragm 184 is 1.8 square inches, sinceit can be shown mathematically that if the diaphragms 224 and 184 havethese effective areas, the brake cylinder device 7, the pistons 59 and15 of which have a diameter of 3.625 inches and 14.0 inches,respectively, will provide for any given service reduction of pressurein the train brake pipe and, therefore, the pipe 150, the same brakingforce for this freight car as those cars provided with a brake cylinderof the type disclosed in U.S. Pat. No. 3,183,795, the piston of whichhas a diameter of 10 inches.

Then the pressure in the chamber 240, and also in the chamber 32 (FIG.2) when the brake control valve device 6 moves to lap position to cutoff the release of fluid under pressure from this chamber 240 (FIG. 3B)and the chamber 32 (FIG. 2) in the brake cylinder device 7 to atmospheremay be calculated as follows:

    67.8 pounds per square inch×1.8 square inches+P.sub.240 ×1 square inch=50 pounds per square inch×1.8 square inches+50 pounds per square inch×1 sq. in.

Then:

P₂₄₀ =17.96 pounds per square inch.

The force to press the brake shoes against the tread surface of thewheels when the pressure in the chamber 240 (FIG. 3B) and chamber 32(FIG. 2) has been reduced to 17.96 pounds per square inch may becalculated as follows:

The fluid pressure force acting in the direction of the right hand onthe left-hand side of the piston 59 (FIG. 2) remains 700 pounds.

The fluid pressure force acting in the direction of the right hand onthe left-hand side of the piston 15 remains 10,320 pounds.

The force of the spring 74 acting in the direction of the left hand onthe right-hand side of the piston 15 remains 400 pounds.

The fluid pressure force acting in the direction of the left hand on theright-hand side of the piston 15 is:

    146.8714 square inches×17.96 pounds per square inch=2,637.61 pounds.

Therefore, the net force acting in the direction of the right hand onthe pistons 59 and 15 is:

    700 pounds+10,320 pounds-2,637.61 pounds-400 pounds=7,982.39 pounds.

Since the braking ratio has been assumed to be 2, the force pressing thebrake shoes against the tread surface of the wheels of the vehicle is:

    7,982.39 pounds×2=15,964.78 pounds.

The brake apparatus disclosed in the above-mentioned U.S. Pat. No.3,175,869 when installed on railway freight cars includes a brakecylinder device of the type shown in U.S. Pat. No. 3,183,795. This brakecylinder device has therein a piston having a diameter of 10 inches andan area of 78.54 square inches which is subject to fluid at a pressureof 50 pounds per square inch when a full service brake application iseffected. Therefore, the fluid pressure force exerted by this piston is:

    78.54 square inches×50 pounds per square inch=3,927 pounds.

Then, assuming a braking ratio of 2, the force pressing the brake shoesagainst the tread surface of the wheels of the vehicle is:

    3,927 pounds×2=7,854 pounds of force.

Therefore, the advantage of the brake apparatus constituting the presentinvention over the brake apparatus disclosed in U.S. Pat. No. 3,175,869is readily apparent since when the pistons 15 and 59 of the brakecylinder device 7 of the present invention have a diameter of 3.625inches and 14.0 inches, respectively, a braking force of 15,964.78pounds is provided whereas when the piston of the brake cylinderdisclosed in U.S. Pat. No. 3,183,795 has a diameter of 10.0 inches, only7,854 pounds of braking force is provided. Thus, when the diameter ofthe piston 15 is only 2.00 inches greater than the diameter of thepiston of the brake cylinder presently used on most railway freightcars, approximately twice as much braking force is provided when thebraking ratio in each case is 2.

Moreover, the brake apparatus constituting the present inventionrequires no separate fluid pressure storage reservoir since the fluidunder pressure for effecting a brake application is stored within thebrake cylinder device 7.

Furthermore, it can be shown mathematically that the volume of fluidunder pressure release from the chamber 32 (FIG. 2) in the brakecylinder device 7 to atmosphere when effecting the above-described brakeapplication is considerably less than the volume of fluid under pressurereleased from the above-mentioned brake cylinder device that has apiston having a diameter of 10 inches.

Accordingly, the volume of the fluid under pressure released from thechamber 32 (FIG. 2) to atmosphere when the pressure in this chamber isreduced from the equalized pressure of 67.8 pounds per square inch gageto a pressure of 17.8 pounds per square inch gage may be calculated asfollows:

    P.sub.1 ×V.sub.1 =P.sub.2 ×V.sub.2 ×V.sub.3 where:

P₁ =Original pressure (82.5 pounds per square inch absolute) in chamber32.

V₁ and V₂ =Volume (292.5144 cubic inches) of chamber 32.

P₂ =Final pressure (32.66 pounds per square inch absolute) in chamber32.

P₃ =Atmospheric pressure (14.7 pounds per square inch absolute) of fluidrelease from chamber 32 to atmosphere.

V₃ =Volume (in cubic inches) of fluid under pressure released fromchamber 32 to atmosphere when pressure in this chamber 32 is reduced to32.66 pounds per square inch absolute.

Then:

82.5 pounds per square inch×292.5144 cubic inches=

32.66 pounds per square inch×292.5144 cubic inches+

14.7 pounds per square inch×V₃

V₃ =992.03 cubic inches.

The above-mentioned 10 inch diameter piston of a conventional brakecylinder device has a stroke of 10 inches. Therefore, the volume of thefluid under pressure in this brake cylinder device when a brakeapplication is in effect is:

    (3.1416×(10).sup.2)/4×10 inch=785.40 cubic inches.

The pressure in this brake cylinder device when a full service brakeapplication is in effect is 64.7 pounds per square inch absolute.

Since all of this fluid under pressure is released to atmosphere when abrake release is effected, the absolute pressure of this fluid releasedto atmosphere is 14.7 pounds per square inch absolute.

Then:

    785.40 square inches×64.7 pounds per square inch=V×14.7 pounds per square inch.

V=3,456.8 cubic inches=Volume of fluid released from a conventionalbrake cylinder device to atmosphere when a brake release is effected.

This volume of 3,456.8 cubic inches is approximately 3.4 times thevolume of 992.03 cubic inches released from the chamber 32 in the brakecylinder device 7. Accordingly, the novel brake cylinder device 7 ismuch more economical in the use of fluid under pressure than theconventional brake cylinder device presently used on most railwayfreight cars.

In view of the foregoing, the superiority of the brake apparatusconstituting the present invention over the brake apparatus disclosed inthe above-mentioned U.S. Pat. Nos. 3,175,869 and 3,183,795 is readilyapparent.

Release of a Brake Application

To effect a release of brakes after effecting a brake application in themanner described above, the engineer will move the handle of theengineer's brake valve device on the locomotive from the position itoccupies in its application zone back to its release position, whereuponthe relay valve device of this brake valve device will effect the supplyof fluid under pressure to the brake pipe 150 (FIG. 1). Fluid underpressure thus supplied to the brake pipe 150 flows therefrom to thechambers 193 (FIG. 3B) and 241 via passageways 157, 156, 195 and 243.

Upon the supply of fluid under pressure to the chambers 193 and 241increasing the pressure therein to a value greater than the respectivepressures of the fluid present in the chambers 192 and 240, thediaphragms 184 and 224 will be deflected upward to cause upward shiftingof the valve stems 185 and 234, annular member 233, exhaust valve seatmember 227 and diaphragm follower plates 189, 191, 237 and 239.

As the follower plate 189 is thus shifted upward, the spring 208 isrendered effective to shift valve 203, annular member 207 and stem 204upward until annular member 207 is seated on valve seat 197 to closecommunication between chambers 41 (FIG. 2) and 192 (FIG. 3B) and thechamber 93 (FIG. 3A).

As the valve stem 185 (FIG. 3B) is thus shifted upward, it will shiftcylindrical valve member 213 upward to unseat annular member 220 fromvalve seat 217.

When annular member 220 is thus unseated from valve seat 217, fluidunder pressure will flow from the chamber 93 (FIG. 3A) above diaphragm85 to atmosphere via passageways 98 and 219 (FIG. 3B), port 218, groove223 on valve member 213, past valve seat 217, counterbore 211,passageways 221 and 94, lower end of counterbore 99 and past shield 95of insect excluder device 96.

Moreover, fluid under pressure will flow from the upper side of thepiston 246 to atmosphere via the passageway 98 and the pathway describedabove thereby rendering the spring 248 effective to shift the upper endof the piston rod 244 into contact with the nut 238 so that the spring248 is thereafter effective to assist in shifting the diaphragms 184 and224 upward and thereby move the annular member 220 further away from thevalve seat 217 which increases the rate of flow of fluid under pressurefrom the chamber 93 to atmosphere via the pathway described above.

As fluid under pressure is thus vented from the chamber 93 (FIG. 3A) toatmosphere, the spring 180 is rendered effective to shift the diaphragmfollower plates 87 and 88 upward away from the valve stems 108, 124,141, 153 and 167.

The valves 101, 102, 103, 104 and 105 will now be shifted upward by therespective springs 110, 128, 138 and 164 to the position in which thesevalves are shown in FIG. 3A.

Upon the return of the valve 101 to the position shown in FIG. 3A, acommunication is established between the chamber 41 (FIG. 2) and 32 inthe brake cylinder device 7.

The return of the valve 102 to the position shown in FIG. 3A disconnectsthe chamber 63 (FIG. 2) from atmosphere and connects this chamber 63 tothe chamber 41.

The return of the valve 103 to the position shown in FIG. 3A disconnectsthe chamber 62 (FIG. 2) from the chamber 41 and establishes acommunication between this chamber 62 and atmosphere so that all fluidunder pressure present in this chamber 62 is vented to atmosphere.

The return of the valve 104 to the position shown in FIG. 3A preventsflow from the brake pipe 150 (FIG. 1) to the chamber 62 which is nowopen to atmosphere, as explained above.

When the charging valve 165 is returned to the position shown in FIG.3A, the fluid in the chamber 41 (FIG. 2) and chamber 192 (FIG. 3B) is atthe hereinbefore-mentioned equalized pressure of 67.8 pounds per squareinch gage which is higher than the pressure in the brake pipe 150(FIG. 1) which is now 50 pounds per square inch gage, as hereinbeforestated.

Consequently, this higher pressure acting on the lower side of the checkvalve 174 within the annular valve seat 176 will lift the check valve174 upward from this seat 176 against the yielding resistance of thespring 173.

When the check valve 174 is thus unseated from its seat 176, fluid underpressure in the chamber 41 (FIG. 2) and chamber 192 (FIG. 3B) will flowto the brake pipe 150 (FIG. 1) via passageways 80 (FIG. 1), 119 (FIG.3A) and 178, past valve seat 176, counterbore 170, hollow valve seatmember 171, past valve seat 113'", counterbore 169, and passageways 179,156 and 157 (FIG. 1) until equalization occurs. This flow to the brakepipe 150 hastens the charging thereof and constitutes an acceleratedbrake release feature.

Subsequent to the above-mentioned equalization, fluid under pressuresupplied to the brake pipe 150 (FIG. 1) by the relay valve of the brakevalve device on the locomotive will flow to the chambers 193 (FIG. 3A)and 241 via passageway 157 (FIG. 1) and passageways 156, 195 and 243(FIGS. 3A and 3B), and to the chamber 41 (FIG. 2) via passageways 157(FIG. 1), 156 (FIG. 3A) and 179, counterbore 169, hollow valve seatmember 171, counterbore 170, choke 175 in check valve 174, andpassageways 178, 119 and 80 (FIG. 1).

Furthermore, fluid under pressure will flow from the passageway 119 tothe chamber 32 (FIG. 2) via counterbore 115 (FIG. 3A), hollow valve seatmember 112, counterbore 106 and passageways 120, 121 (FIG. 1) and 77(FIG. 2), and also to the chamber 192 (FIG. 3B) via passageways 147 and194.

It will be noted that some of the fluid under pressure supplied to thepassageway 120 will flow therefrom to the chamber 240 above thediaphragm 224 via the passageway 242.

When the chambers 192, 193, 240 and 241 are all charged to the normalpressure carried in the brake pipe 150 (FIG. 1), the springs 214 (FIG.3B), 226 and 248 will return the diaphragms 184 and 224, the diaphragmfollower plates 189, 191, 237 and 239, the valve stems 185 and 234, thevalve member 213, the exhaust valve seat member 227, the piston 246 andpiston rod 244, to the position shown in FIG. 3B in which the annularmember 220 is seated on valve seat 217 and exhaust valve seat 229 isseated on annular member 233 so that chamber 93 (FIG. 3A) and chamber240 (FIG. 3B) are cut off from atmosphere.

With fluid under pressure vented from the chamber 62 (FIG. 2) toatmosphere and supplied to the chambers 41, 63 and 32 from the brakepipe 150 (FIG. 1), the release spring 74 (FIG. 2) is rendered effectiveto return the piston 59 and 15 in the brake cylinder device 7 to theposition shown in FIG. 2 thereby releasing the brakes on the vehicle.

It should be noted that as the piston 15 is returned by the spring 74 tothe position shown in FIG. 2, the check valve device 42 prevents flow offluid under pressure from the chamber 41 to the chamber 32 which ischarged with fluid under pressure from the brake pipe 150 (FIG. 1) inthe manner explained above.

The various elements of the brake control valve device 6 and the brakecylinder device 7 now occupy the position in which they are shown in thedrawings and the brakes on the vehicle are released.

Furthermore, the chambers 32, 41 and 63 in the brake cylinder device 7(FIG. 2) are charged to the normal fully charged pressure carried in thebrake pipe 150 (FIG. 1) and all fluid under pressure is vented from thechamber 62 (FIG. 2) in this brake cylinder device 7.

While one specific example of the diameters of the pistons 59 and 15 inthe novel brake cylinder device 7 has been given by way of illustration,it should be noted that the braking force provided by this novel brakecylinder device may be increased or decreased accordingly as thediameter of one or both of these pistons is increased or decreased.

Having now described the invention, what I claim as new and desire tosecure by Letters Patent, is:
 1. A fluid pressure brake apparatus forcontrolling braking of a vehicle, said brake apparatus comprising:(a)brake pipe normally charged to a chosen pressure, (b) braking meanshaving:(i) a pair of fluid motors of unequal size, each having therein amovable abutment operatively connected to the movable abutment in theother fluid motor, said abutments being operative .[.co-jointly.]..Iadd.jointly .Iaddend.to effect a brake application to a degree inaccordance with the sum of two differential fluid pressure forces actingin the same direction on .Iadd.one and the other of .Iaddend.therespective corresponding sides of said abutments, (ii) .[.a.]. one-wayflow valve .[.carried by the movable abutment of the larger fluid motorto enable.]. .Iadd.means for enabling .Iaddend.flow of fluid underpressure from a first fluid pressure storage reservoir provided in saidlarger fluid motor at .Iadd.said .Iaddend.one side of the largerabutment to a second fluid pressure storage reservoir at .[.the.]..Iadd.said .Iaddend.other side of said larger abutment, and (iii)biasing means acting on said one side of said larger abutment andeffective to normally bias both of said abutments to a brake releaseposition, and (c) a brake control valve device having valve meansoperable in response to charging said brake pipe to said certain chosenpressure to effect the supply of fluid under pressure from said brakepipe to said first and second storage reservoirs .[.and to one side ofthe smaller abutment.]. and the release of fluid under pressure from.[.the.]. .Iadd.said .Iaddend.other side .[.thereof.]. .Iadd.of thesmaller abutment.Iaddend., said valve means being operable in responseto a reduction of the pressure in said brake pipe from said chosenpressure to .[.simultaneously.]. cause the .[.release of fluid underpressure from said one side of said smaller abutment, and the.]..Iadd.supply of fluid under pressure from said second storage reservoirto said other side of said smaller abutment and .Iaddend.release offluid under pressure from said first fluid pressure storage reservoir atsaid one side of said larger abutment to reduce the pressure therein toa degree corresponding to the degree of reduction of the pressure insaid brake pipe whereby fluid under pressure acting on the respectiveother side of said pair of tandem-arranged abutments establish a fluidpressure braking force corresponding to the sum of the respectivedifferential fluid pressure forces acting on said respective other sidesof said pair of tandem-arranged abutments.
 2. A fluid pressure brakeapparatus, as recited in claim 1, further characterized in that thesmaller of said fluid motors is disposed within said larger fluid motor.3. A fluid pressure brake apparatus, as recited in claim 1, furthercharacterized in that the smaller of said fluid motors is disposedwithin said second fluid pressure storage reservoir.
 4. A fluid pressurebrake apparatus, as recited in claim 1, further characterized in thatsaid operatively-connected abutments are arranged in tandem.
 5. A fluidpressure brake apparatus, as recited in claim 1, further characterizedby a pipe bracket having a pair of parallel spaced-apart faces to one ofwhich is secured said braking means and to the other of which is securedsaid brake control valve device.
 6. A fluid pressure brake apparatus, asrecited in claim 1, further characterized in that said brake controlvalve device comprises:(a) a movable abutment for effecting operation ofsaid valve means; and (b) an application and release control valvemechanism operatively responsive to a reduction of the pressure in saidbrake pipe to cause the supply of fluid under pressure from said secondfluid pressure storage reservoir to said movable abutment to cause saidmovable abutment to operate said valve means.
 7. A fluid pressure brakeapparatus, as recited in claim 1, further characterized in that saidbrake control valve device comprises:(a) a movable abutment foreffecting operation of said valve means, and (b) an application andrelease control valve mechanism operatively responsive to a reduction ofthe pressure in said brake pipe and comprising:(i) a first valve foreffecting the supply of fluid under pressure from said first and secondstorage reservoirs to said movable abutment for effecting operation ofsaid valve means, (ii) a second valve for effecting a release of fluidunder pressure from said first fluid pressure storage reservoir toatmosphere to render the fluid under pressure in said second fluidpressure storage reservoir effective to increase the differential fluidpressure force acting on said other side of said larger abutment, and(iii) a pair of spaced-apart movable abutments for effecting operationof said first and second valves in response to a reduction of pressurein said brake pipe, one of said abutments being subject on itsrespective opposite sides to the pressure in said second fluid pressurestorage reservoir and in said brake pipe, and the other of saidabutments being subject on its respective opposite sides to the pressurein said first fluid pressure storage reservoir and in said brake pipe.8. A fluid pressure brake apparatus, as recited in claim 1, furthercharacterized in that said valve means of said brake control valvedevice comprises:(a) a first valve for controlling flow of fluid underpressure from said second fluid pressure storage reservoir to said firstfluid pressure storage reservoir, (b) a second valve for controllingflow of fluid under pressure from said second fluid pressure storagereservoir to said one side of said movable abutment of the smaller ofsaid pair of fluid motors and the release of fluid under pressure fromsaid one side to atmosphere, (c) a third valve for controlling flow offluid under pressure from said other side of said movable abutment ofthe smaller of said pair of fluid motors to atmosphere and the supply offluid under pressure from said second fluid pressure storage reservoirto said other side of said movable abutment of the smaller of said pairof fluid motors, (d) a fourth valve for controlling flow of fluid underpressure from said brake pipe to said other side of said movableabutment of the smaller of said pair of fluid motors, and (e) a fifthvalve for controlling flow of fluid under pressure from said brake pipeto said fluid pressure storage reservoirs.
 9. A fluid pressure brakeapparatus, as recited in claim 8, further characterized in that saidvalve means comprises:(a) a one-way flow valve disposed between saidfourth valve and said other side of said movable abutment of the smallerof said pair of fluid motors to provide for flow of fluid under pressurefrom said brake pipe to said other side of said movable abutment andprevent backflow of fluid under pressure from said other side to saidbrake pipe, and (b) a choke so disposed between said one-way flow valveand said other side as to control the rate of flow of fluid underpressure to said other side without restricting the rate of release offluid under pressure from said other side to atmosphere by said thirdvalve.
 10. A fluid pressure brake apparatus, as recited in claim 8,further characterized in that said valve means comprises:(a) a one-wayflow valve disposed between said fifth valve and said second fluidpressure storage reservoir, and (b) a choke for controlling flow offluid under pressure from said storage reservoirs to said brake pipewhereby said choke and said one-way valve cooperate to provide for arestricted rate of flow of fluid under pressure from said brake pipe tosaid storage reservoirs while said reservoirs are being charged fromsaid brake pipe to said certain chosen pressure, and an unrestrictedrate of flow of fluid under pressure from said storage reservoirs tosaid brake pipe upon said first and fifth valves establishing acommunication through which fluid under pressure may flow from saidstorage reservoirs to said brake pipe subsequent to a reduction of thepressure in said brake pipe to a value less than the pressures in saidstorage reservoirs, said flow from said reservoirs to said brake pipeproviding an accelerated brake release.
 11. A brake cylinder devicecomprising:(a) a first hollow cylindrical member, (b) a second hollowcylindrical member coaxially disposed within said first hollowcylindrical member, (c) a first movable abutment disposed within saidfirst hollow cylindrical member and cooperating therewith to form afirst and a second fluid pressure chamber on the respective oppositesides of said first movable abutment, (d) a second movable abutmentdisposed within said second hollow cylindrical member and cooperatingtherewith to form a first and a second fluid pressure chamber on therespective opposite sides of said second movable abutment, (e) meansoperably connecting said first and second movable abutments, and (f) aone-way flow valve means to enable flow of fluid under pressure fromsaid first fluid pressure chamber at one side of said first movableabutment to said second fluid pressure chamber at the opposite sidethereof upon the shifting of both of said movable abutments in onedirection in response to the supply of fluid under pressure to thecorresponding second chamber at the other side of said second movableabutment.
 12. A brake cylinder device, as recited in claim 11, furthercomprising:(a) a pair of pressure heads, (b) means securing said pair ofpressure heads to the respective opposite ends of said first hollowcylindrical member, and (c) means securing said second hollowcylindrical member to one of said pressure heads.
 13. A brake cylinderdevice, as recited in claim 11, further characterized in that saidone-way flow valve means is carried by said first movable abutment. 14.A brake cylinder device, as recited in claim 11, further characterizedin that said first movable abutment is provided with at least one portextending therethrough and with an annular valve seat disposed insurrounding relation to said at least one port, and said one-way flowvalve means comprises:(a) a resilient annular valve member for engagingsaid annular valve seat, (b) a spring seat so secured to said firstmovable abutment as to clamp the inner periphery of said annular valvemember between said spring seat and said first movable abutment, and (c)biasing means interposed between said spring seat and said annularmember for normally biasing said annular valve member into seatingcontact with said annular valve seat.
 15. A brake cylinder device, asrecited in claim 11, further characterized by conduit means formed insaid first hollow cylindrical member through which fluid under pressuremay be supplied to one side of said first movable abutment.
 16. A brakecylinder device, as recited in claim 11, further characterized by firstconduit means formed in said first hollow cylindrical member throughwhich fluid under pressure may be supplied to one side of said firstmovable abutment, and by second conduit means formed in said secondhollow cylindrical member through which fluid under pressure may besupplied to one side of said second movable abutment.
 17. A brakecylinder device, as recited in claim 12, further characterized by firstconduit means formed in said first hollow cylindrical member throughwhich fluid under pressure may be supplied to one side of said firstmovable abutment, and by second conduit means formed in one of said pairof pressure heads through which fluid under pressure may be supplied tothe other side of said first movable abutment.
 18. A brake cylinderdevice, as recited in claim 12, further characterized by first conduitmeans formed in said second hollow cylindrical member through whichfluid under pressure may be supplied to one side of said second movableabutment, and by second conduit means formed in one of said pair ofpressure heads through which fluid under pressure may be supplied to theother side of said second movable abutment.
 19. A brake cylinder device,as recited in claim 14, further characterized in that said meansoperably connecting said first and second movable abutments comprises arod removably-connected at one end to said spring seat and at the otherend to said second movable abutment.
 20. For use with a brake cylinderdevice having a pair of hollow coaxially-arranged cylindrical members ofunequal length in the outer and longer of which is slidably mounted onone side of the smaller a first movable abutment carrying thereon acheck valve to provide for flow of fluid under pressure from one sidethereof to the other and being operably-connected to a second movableabutment slidably mounted in the inner cylindrical member, and a brakerelease spring that is interposed between the one side of the firstabutment and one of a pair of pressure heads that are secured to therespective opposite ends of the outer cylindrical member whereby thispair of pressure heads cooperate with the outer cylindrical member andthe first abutment to form on the respective opposite sides of thisfirst abutment a pair of fluid pressure storage reservoirs, the brakerelease spring being effective to shift both of the movable abutments toa brake-release position in response to the release of fluid underpressure from one side of the second movable abutment and the supply offluid under pressure to the other side of this second abutment, a brakecontrol valve device comprising:(a) fluid pressure operated valve meanshaving one position in which fluid under pressure can flow from a sourceof fluid under pressure to the other side of the second movable abutmentand the pair of fluid pressure storage reservoirs to effect the chargingthereof, and shiftable to a second position in which said other side ofthe second abutment is open to atmosphere, and fluid under pressureflows from both of the storage reservoirs to the one side of the secondabutment until equalization of pressure in the storage reservoirs and onsaid one side of the second abutment occurs, and (b) an application andrelease control valve mechanism operative to effect the supply of fluidunder pressure from one of the pair of storage reservoirs to saidfluid-pressure-operated valve means to cause the operation thereof fromits first position to its second position, and the release of fluidunder pressure from the other storage reservoir to atmosphere toincrease the differential fluid pressure force established by the fluidunder pressure in the one storage reservoir on the first movableabutment whereby said abutments establish a fluid pressure braking forceproportional to the degree of the reduction of the pressure in the otherstorage reservoir by the release of fluid under pressure therefrom toatmosphere.
 21. A brake control valve device, as recited in claim 20,further characterized in that said fluid-pressure-operated valve meanscomprises:(a) a plurality of valves for controlling the supply of fluidunder pressure to and the release of fluid under pressure from said pairof fluid pressure storage reservoirs, and to and from said one side andsaid other side of said second movable abutment of the brake cylinderdevice, and (b) a movable abutment for simultaneously operating saidplurality of valves when supplied with fluid under pressure by saidapplication and release control valve mechanism.
 22. A brake controlvalve device, as recited in claim 20, further characterized in that saidfluid-pressure-operated valve means comprises:(a) four annular hollowvalve seat members having a flange at one end and an annular valve seatat the other, (b) four annular stops, each arranged in coaxialsurrounding relationship with one of said annular hollow valve seatmembers, (c) a first set of four biasing means each arranged to normallybias the flange at one end of one annular hollow valve seat memberagainst a corresponding annular stop, (d) four valves each so disposedin coaxial relationship with one of said annular hollow valve seatmembers as to be moved into seating contact with the annular valve seatat the other end of said seat member, (e) a second set of four biasingmeans each disposed between one of said valves and a corresponding oneof said annular valve seat members so as to bias each valve away fromits annular valve seat, (f) a valve stem secured to each of said valves,and (g) a movable abutment so disposed with respect to said valve stemsas to effect shifting of all of said valve stems and the respectivevalve secured thereto until each valve is seated on its correspondingvalve seat whereby each valve controls flow of fluid under pressure toone side of one of said abutments.
 23. A brake control valve device, asrecited in claim 20, further characterized in that said application andrelease control valve mechanism comprises:(a) a first valve foreffecting the supply of fluid under pressure from that one of said pairof fluid pressure storage reservoirs that is at said other side of saidfirst abutment to said fluid-pressure-operated valve means to causeshifting thereof from its said first to its said second position, (b) asecond valve for effecting a release of fluid under pressure from theother one of said pair of fluid pressure storage reservoirs toatmosphere to render the fluid under pressure in said one of said pairof storage reservoirs effective to increase the differential fluidpressure force acting on the first movable abutment thereby increasingthe degree of braking force provided by the brake cylinder device, (c) apair of spaced-apart coaxial movable abutments, one of which is subjecton its respective opposite sides to the pressure in said one of saidpair of fluid pressure storage reservoirs and the pressure in a separatesource of fluid under pressure, and the other which is subject on itsrespective opposite sides to the pressure in said other one of said pairof fluid pressure storage reservoirs and the pressure in said separatesource, between which pair of abutments said first and second valvemeans are so disposed that shifting of said pair of abutments in onedirection in response to a reduction of the pressure in said separatesource effects operation of said first and second valve means, and (d)means associated with said second valve means that insures sequentialopening of said first and second valve means and subsequent closing ofsecond valve means without effecting closing of said first valve means.24. A brake control valve device, as recited in claim 22, furthercharacterized by a fifth valve and valve seat for controlling flow offluid under pressure from a separate source of fluid under pressure tothe one side of the second abutment, and means for limiting flow offluid under pressure from said separate source of fluid under pressureto said one side of the second abutment.
 25. A brake control valvedevice, as recited in claim 22, further characterized by a choke carriedby a spring-loaded check valve, and a valve seat for the check valve,said seat being disposed in series with and on the downstream side ofthat one of said four valves that controls flow to said other side ofsaid first abutment to provide for a restricted flow of fluid underpressure from a separate source of fluid under pressure to said otherside and a subsequent unrestricted flow of fluid under pressure fromsaid other side of said separate source.
 26. A brake control valvedevice, as recited in claim 23, further characterized by means biasingsaid pair of abutments in a direction opposite said one direction and byfluid-pressure-operated means supplied with fluid under pressure by saidfirst valve means for rendering said means ineffective to bias said pairof abutments in said direction opposite said one direction.
 27. A brakecontrol valve device, as recited in claim 22, further characterized by arelease valve device operable upon shifting of said abutments in adirection opposite said one direction to release fluid under pressurefrom said fluid-pressure-operated valve means to atmosphere, and meansfor shifting said valve means from its said second position to its saidfirst position upon the release of fluid under pressure therefrom.
 28. Abrake control valve device, as recited in claim 23, furthercharacterized in that the effective area of said one of said pair ofabutments is a chosen multiple of the effective area of said other ofsaid pair of abutments.
 29. A brake control valve device, as recited inclaim 23, further characterized in that the effective area of said oneof said pair of abutments is 1.8 times the effective area of said otherof said pair of abutments.
 30. A brake control valve device, as recitedin claim 24, further characterized in that said fifth valve comprises acheck valve and said limiting means comprises a spring for normallybiasing said check valve into seating engagement with said valve seat.31. A brake control valve device, as recited in claim 26, furthercharacterized in that said biasing means comprises a spring, and saidfluid-pressure-operated means comprises a piston having a piston rodextending from one side thereof into engagement with one of said pair ofabutments, said piston rod being moved out of engagement with said oneabutment in response to the supply of fluid under pressure to said oneside of said piston by said first valve means.
 32. A brake control valvedevice, as recited in claim 27, further characterized in that said valvemeans comprises:(a) an annular valve seat, and (b) a hollow cylindricalmember having formed integral therewith intermediate its ends a collarfor engaging said annular valve seat, one end of said hollow cylindricalmember abutting one side of one of said pair of abutments, said hollowcylindrical member enabling the respective opposite ends of said memberto be subject to the pressure of the fluid acting on said one side ofsaid one abutment thereby enabling balancing of said member by saidfluid acting on said one side of said one abutment. .Iadd.
 33. A fluidpressure brake apparatus, as recited in claim 1, further characterizedin that said valve means is operable to effect the supply of fluidpressure to said one side of said smaller abutment in response tocharging said brake pipe to said certain chosen pressure to urge saidsmaller abutment toward said release position, and to effect the releaseof fluid pressure from said one side of said smaller abutment inresponse to a reduction of the pressure in said brake pipe from saidchosen pressure. .Iaddend.